Clemmons A J, Thompson D L, Johnson L
Department of Veterinary Anatomy and Public Health, College of Veterinary Medicine Texas A&M University 77843-4458, USA.
Biol Reprod. 1995 Jun;52(6):1258-67. doi: 10.1095/biolreprod52.6.1258.
Gross observation of testicular parenchyma of 1.5- to 2-yr-old horses reveals both light and dark regions. If this gross, differential shading reflects quantitative differences in the development of spermatogenesis and interstitial cell populations, the horse may prove to be a useful model for study of the paracrine relationships associated with initiation of spermatogenesis. The objective of this study was to characterize seminiferous tubules and interstitium of testes with gross, differential shading. Testes with both light and dark regions of parenchyma were obtained from horses 1.5-2 yr old and compared to parenchyma of fetal, 2-yr-old, or 5-yr-old horses. Stereology was used on tubular and interstitial components, and luminal development of seminiferous tubules was scored. Volume density of seminiferous tubules, percentage of tubules with large vacuoles or a complete lumen, and number of primary spermatocytes per gram were greater (p < 0.05) in light parenchyma than in dark parenchyma. The percentage of tubules with no lumen and the percentage of parenchyma occupied by interstitial space were greater (p < 0.05) in fetal and dark parenchyma than in light parenchyma. The number of Leydig cells per gram parenchyma was similar (p > 0.05) in both light parenchyma and dark parenchyma. A greater percentage (p < 0.05) of other (nonvascular, non-Leydig, nonmacrophage) cells was found in the dark parenchyma than in light parenchyma or in testes of 2- or 5-yr-old horses. The volume density of macrophages was notably greater (p < 0.05) in fetal and dark parenchyma than in light parenchyma or in testes from older horses. Variation in development of seminiferous tubules was not associated with the volume density of blood vessels. In conclusion, the gross, differential shading of equine testicular parenchyma with its corresponding differences in seminiferous tubular development is a clear example of the effect of local factors leading to the local initiation of spermatogenesis.
对1.5至2岁马匹的睾丸实质进行大体观察，可发现浅色和深色区域。如果这种大体上的差异阴影反映了精子发生和间质细胞群体发育在数量上的差异，那么马可能被证明是研究与精子发生起始相关旁分泌关系的有用模型。本研究的目的是通过大体上的差异阴影来描述睾丸的生精小管和间质。从1.5至2岁的马匹获取具有浅色和深色实质区域的睾丸，并与胎儿、2岁或5岁马匹的实质进行比较。对小管和间质成分进行体视学分析，并对生精小管的管腔发育进行评分。浅色实质中生精小管的体积密度、有大液泡或完整管腔的小管百分比以及每克初级精母细胞的数量均高于深色实质（p<0.05）。胎儿和深色实质中无管腔的小管百分比以及间质所占实质的百分比高于浅色实质（p<0.05）。浅色实质和深色实质中每克实质的莱迪希细胞数量相似（p>0.05）。与浅色实质或2岁或5岁马匹的睾丸相比，深色实质中其他（非血管、非莱迪希、非巨噬细胞）细胞的百分比更高（p<0.05）。胎儿和深色实质中巨噬细胞的体积密度明显高于浅色实质或老年马匹睾丸（p<0.05）。生精小管发育的差异与血管的体积密度无关。总之，马睾丸实质的大体差异阴影及其在生精小管发育上的相应差异是局部因素导致精子发生局部起始的明显例子。
